The present invention is directed to an inking ribbon for transferring color, under the influence of heat, comprising a carrier layer, an ink (or color) layer, and an exothermally decomposabIe component that promotes the transfer of the color when heat is applied.
European Patent Application No. EP-A-0 150,383 discloses an inking ribbon. In the inking ribbon disclosed, an ink layer, applied on a carrier layer, contains an aromatic azido compound that exothermally decomposes with a reaction temperature in the range from 170.degree. C. through 200.degree. C. given the application of heat with a thermal printing head and thereby supplies additional heat for softening the ink layer.
U.S. Pat. No. 4,525,722 discloses a heat-sensitive inking ribbon having hydrazone derivatives as an exothermally decomposable component in the ink layer, or as an intermediate layer between the carrier layer and the ink layer. The decomposition temperature of the exothermally decomposable component lies in the range of between 150.degree. C. and 200.degree. C. The patent specifies 200 J/g as the typical value of the specific energy being thereby released.
JP-A-59 165690 (Patent Abstracts of Japan, Vol. 9, No. 18 (M-353) (1741), 25 Jan. 1985), as well as, "IBM Technical Disclosure Bulletin", Vol. 19, No. 2, July 1976, page 672, disclose the use of cellulose nitrate (also known as "nitrocellulose") as an adhesion promotor between the carrier layer and the ink of a heat-sensitive inking ribbon. The cellulose nitrate therein, however, only functions to promote adhesion and is not exothermally reactive.